Solar Panel Combiner

[claychps]

Hi all,

 I made a combiner box out of a Square D box that takes HOM breakers. I put in (4)15a, one for each of the HF panels and one for a homemade panel. Did I mess up because they are not DC rated?

Robert  

[dnix71]

Are you using HF panels from the 45 watt kit or some of the bigger ones they sell?

The 45 watt kit panels only put out an amp or so. A 15 amp breaker won't do much except provide an easy disconect.

The HF panels don't have blocking diodes built in, either, the PDU (controller box) that comes with the kit has the blocking diode and fuses.

What's the purpose of your "combiner box?"

[wpowokal]

In my opinion no, I base that on the fact that you will not be switching them very often.

The difficulty with using AC switches with DC lies in the fact that DC is hard to interrupt, when you open the switch an arc follows the contact as it opens. In AC there is zero volts 50/60 times per second which helps break the arc. DC switches have a longer break gap and stronger springs, generally.

My advice would be to feel the switches in service and if they are not hot then a good contact is being made, AC switches generally have less spring tension than DC.

allan down under

[commanda]

In AC there is zero volts 50/60 times per second

That should read "In AC there is zero volts 100/120 times per second (50/60 Hz)".

An AC waveform crosses zero twice for every full cycle.

Amanda

[wooferhound]

My opinion is that combining solar panels with a circuit breaker panel is both useless and expensive. Harbor Freight Solar panels put out less than 1 amp and fuses are not needed. Solar panels are combined and isolated with diodes like this...

http://www.fieldlines.com/story/2008/6/24/0179/40235

However everything going Into & Out-of the battery should be fused because your battery can produce over 1000 amps. Every branch of everything that connects to the battery is fused since the chance of fire with a Short Circuit is a very real possibility. Don't use circuit breakers unless they are specifically rated for use with DC voltage. Here is what my Fusebox looks like...

http://www.fieldlines.com/story/2009/3/18/232910/066

[wooferhound]

and another diode isolated solar combiner box...

http://www.fieldlines.com/story/2004/12/12/232315/76

[claychps]

Thanks all,

  Yes, it is just the 45w basic panel kit. I agree with Woof, guess it is a waste of money so on to building a diode combiner box. I'll find a use for the AC breakers somewhere, or swap meet them. From now on I'll search this board more and only post really hard to figure out questions. I know automotive electricity, but when I can burn down or explode something due to lack of knowledge, I get apprehensive. Read,read,read and read some more I guess.

Robert